Heater Voltage Control for Vacuum Discharge Prevention
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Solution Overview
Problem
The existing substrate processing technologies face issues with abnormal discharge and dielectric breakdown between electrodes in vacuum chambers during the degassing process, leading to power supply tripping and reduced throughput.
Innovation Solution
Implementing a discharge countermeasure process that involves stopping and restarting the voltage application to the heater based on Paschen's law to prevent abnormal discharge, by determining the discharge pressure range and controlling the voltage application accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If voltage is continuously applied to the heater during vacuum processing, then heating efficiency is improved, but abnormal discharge and dielectric breakdown occur between electrodes
Solution Approach 1:
The patent implements periodic action by intermittently applying voltage to the heater based on pressure monitoring. The control unit stops voltage application when pressure enters a discharge risk range and resumes it when pressure exits this range, preventing abnormal discharge while maintaining heating efficiency during safe operating conditions.
Solution Approach 2:
The patent employs feedback control where the control unit continuously monitors the pressure inside the vacuum chamber and adjusts voltage application to the heater accordingly. When pressure indicates a discharge risk, voltage is stopped; when pressure is safe, voltage is applied, creating a closed-loop control system that balances heating efficiency with electrode protection.
2Reliability
If voltage application is stopped to prevent discharge, then electrode safety is improved, but heating continuity is disrupted and throughput decreases
Solution Approach 1:
The system uses periodic action by temporarily stopping voltage only when pressure enters the discharge risk range, then resuming it immediately when pressure exits this range. This minimal interruption approach maintains heating continuity and processing throughput while ensuring electrode safety during critical pressure conditions.
Solution Approach 2:
The control unit automatically monitors pressure and self-regulates voltage application without external intervention. The system serves itself by detecting discharge risks and autonomously adjusting voltage application, minimizing manual intervention and maintaining continuous processing operations.
3Reliability
If pressure is continuously monitored to prevent discharge, then electrode protection is improved, but system complexity increases
Solution Approach 1:
The control unit performs self-service by automatically monitoring pressure and regulating voltage application without requiring external complex control systems. The integrated control approach uses existing pressure sensors and control circuits to autonomously manage voltage application, protecting electrodes while minimizing added system complexity.
Solution Approach 2:
The patent applies parameter changes by monitoring pressure (a physical parameter) and using this information to dynamically adjust voltage application (another parameter). This straightforward parameter-based control approach provides effective electrode protection through a simple cause-effect relationship between pressure monitoring and voltage regulation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents abnormal discharge and electrode burnout, ensuring continuous heating of the substrate and maintaining throughput by automatically managing voltage application within the discharge pressure range.
Implementation Method 1
the electrode being connected to the stage and applying a voltage to the heater
Implementation Method 2
the discharge pressure range being determined based on Paschen's law as a pressure range in which discharge occurs in the vacuum chamber
Implementation Method 3
a vacuum chamber, a stage disposed in the vacuum chamber
Data Source
AI summary
With respect to a substrate processing method performed by a substrate processing apparatus including a vacuum chamber, a stage disposed in the vacuum chamber and including a heater, a gas supply that supplies a gas into the vacuum chamber, an exhaust device that exhaust the gas in the vacuum chamber, and an electrode installed in the vacuum chamber, the electrode being connected to the stage and applying a voltage to the heater, the substrate processing method includes performing a discharge countermeasure process including lowering the voltage applied to the heater while a pressure in the vacuum chamber is within a discharge pressure range, the discharge pressure range being determined based on Paschen's law as a pressure range in which discharge occurs in the vacuum chamber, and applying the voltage to the heater in response to determining that the pressure in the vacuum chamber is out of the discharge pressure range.